In mounting apparatuses that mount a workpiece, such as an electric part, onto a substrate, machining apparatuses that machine a workpiece as a machining target, and other apparatuses, a linear motor is used as a means that drives a bead portion, which is brought into contact with or close to a workpiece, in the vertical direction. In such mounting apparatuses and machining apparatuses, a load to be applied to a workpiece when the head portion is pressed against the workpiece is controlled by increasing and decreasing the thrust that is produced by the linear motor. On the head portion operating in the vertical direction, there acts a downward external force in the vertical direction by gravitation. Therefore, in controlling the thrust of the linear motor, control in consideration of the weight of the head portion is required. To make the control in consideration of the weight of the head portion, there are cases where a balancer for equilibrium in accordance with the weight of the head portion is used (Patent Document 1).